Last summer, Danilo Gallinari and his team of doctors gambled on a nontraditional ACL surgery. On Tuesday, they lost that gamble when the Nuggets forward had to go back under the knife.

Gallinari underwent a standard reconstructive ACL procedure Tuesday morning on his left knee, ending his season and resetting his rehabilitation process back to square one. It's a blow to the Nuggets, but they had played without him the entire season, though they were hopeful he would be back by the stretch run. It's a bigger blow to Gallinari, who at times appeared to be closing in on a return to the court.

On his Facebook page, translated from Italian, Gallinari wrote, "I would have preferred (it) not to happen and am partly annoyed." He said that during rehab he continued to feel a "slight instability" in the knee and that "started creating doubt" that he'd be back and playing anytime soon.

"It's disappointing," Nuggets coach Brian Shaw said, "the fact that we know how hard he worked rehabbing over the last few months to try to get back for this season. We feel for him, and know how tough a situation that is to deal with."

Gallinari originally had a procedure called healing response, a repair procedure that hinges on stimulating the ACL to heal itself rather than surgically reconstructing it.

Gallinari and his doctors, none of whom were affiliated with the team, were so excited at the outcome that he publicly voiced expectation of playing by the end of November. Once Gallinari got under the care of Nuggets doctors and trainers at the start of training camp, timetables were eliminated. He was put on a careful, gradual regimen in attempt to get him back on the court.

Gallinari's summer prediction came and went. In an interview with The Post in November, he said he knew he wasn't returning anytime soon.

"As you are able to see, it was the thought of a guy who had this injury for the first time. I had no experience with this injury, this rehab," he said. "That was just my prediction. But as you can see, I was completely wrong. It's day by day, week by week. You cannot really predict. You've got to just listen to your knee."

Finally he came to the realization that another procedure was needed.

"It was recently determined that the procedure that Danilo underwent on his knee this past summer was insufficient," Nuggets general manager Tim Connelly said in a statement. "Danilo's knee required that he undergo reconstruction of the ACL, which was successfully completed (Tuesday) morning. Knowing Danilo's drive and work ethic, we look forward to a full recovery and a healthy return to the court next season."

Danilo Gallinari (Hyoung Chang, Denver Post file)

An insurance policy had already kicked in Jan. 11, allowing the Nuggets to recoup 80 percent of his salary from that point to the end of the season. That will amount to around $4.5 million.

But that is little solace to a team which will not have its second-leading scorer from a year ago for the entire season.

"I had hope, but I was realistic about the fact that it may not happen as well," Shaw said. "The fact that he hadn't been here for any parts of it, I always kind of take the worst-case scenario. So we always did understand that this was a possibility that he may not be back. It's kind of a tease as you watched him seemingly get closer and actually get out here on the floor, running up and down and shooting and things like that. Your mind starts to said, 'OK, I can see him in the lineup doing this, doing that.' "

The Nuggets, 20-20 this season, return to action Thursday night at Portland.

"He's a great player and we need him," forward J.J. Hickson said. "But we're going to have to win without him. We're going to have to make this playoff push without him. We should be able to get it done, but when someone of that caliber goes down, we're going to have to pick up our game a little bit more to make up for it."